Our pharmaceutical laboratory has two moisture analyzers in use; one is Shimadzu MOC3u (MC-A), and the other is Mettler-Toledo HC103 (MC-B). A sample from the same batch was put on each instrument to determine its moisture content, and the two brands seem to have significantly different results: MC-A resulted in about 2.1% MC, and redrying resulted in a lower value at 1.5% MC MC-B, on the other hand, resulted in about 2.2% MC, but upon redrying resulted in almost the same value for MC at about 2.1% MC.

The settings for both instruments are set at 70°C for 8 minutes, and both are also recently calibrated and found to be within specifications.

Is there a specific reason why there is a significant difference in the results for the moisture content results? Which of the two results should we accept, and would the other result be invalid?

  • 2
    I think you'd be better off talking to tech support for the two machines involved. This question is basically a tech support question, which isn't on topic here. Plus the odds of finding someone here who can answer it are very low, and even if someone can answer it, they would probably have to engage in a long discussion with you about it, which this site isn't designed for. I think the machine manufacturers would be your best bet.
    – Carey Gregory
    Commented May 28, 2022 at 16:30
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    You say the machines are calibrated and within spec; what's the spec? How close are the standards to the moisture contents you're measuring? Are the results systematically different or just one test of each?
    – Bryan Krause
    Commented May 28, 2022 at 20:44
  • 1
    I’m voting to close this question because it is basically a tech support question rather than a medical science question. Commented Jun 1, 2022 at 5:53


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